Apparatus for the manufacture of rubber plates



y 16, 1940- R. w. BROWN 2,208,536

APPARATUS FOR -THE MANUFACTURE OF RUBBER PLATES Filed April 20, 1936 5 Sheets-Sheet 1 AT: ORNEY R. W. BROWN APPARATUS FOR THE MANUFACTURE OF RUBBER PLATES Filed April 20, 1956 5 Sheets-Sheet 2 .4 E A 7 7 .imms. ,4 EIIE rw W W 3 6 APPARATUS FOR THE MANUFAETURE 0F RUBBER PLATES Filed Ap ril 20, 1936 S Sheets-Sheet 5 M m IW /A A W 0 W w v1 5 5 4 w 3 p. n g m 6 .J 4 a! I 6 5 IM 6 I: 1 m A 1 i J 4 6 July 16, 1940. R. w. BROWN APPARATUS FOR THE MANUFACTURE OF-RUBBER PLATES s Sheets-Sheet 4 Filed April 20, 1936 HHHI I I I HHHI I llllllllll? ll l ll.

ATTO RNEY July 16, 1940. R. w. BROWN APPARATUS FOR THE MANUFACTURE OF RUBBER PLATES 5 Sheets-Sheet 5 Filed April 20, 1936 2 www INQENTOR I W. BAo-hfn/ ATTORNEY Patented July 16, 1940 UNITED STATES APPARATUS FOR THE MANUFACTURE OF RUBBER PLATES Roy W. Brown, Akron, Ohio, assignor to The Firestone Tire & Rubber Company, Akron,

Ohio, a corporation of Ohio Application April 20, 1936, Serial No. 75,273

3 Claims.

This invention relates to methods of and apparatus for the manufacture of rubber plates, and more especially it relates to procedure and apparatus for making relatively'thin plates or sheets of relatively stiff rubber composition.

The invention is of primary utility in the manufacture of storage battery separator plates of relatively stiff, microporous rubber wherein the latter is produced directly from rubber latex.

The product, the composition from which it is made, and the laboratory method of manufacture are clearly set out in the patent to H. W. Greenup, No. 1,959,160, of May 15, 1934. In some of its aspects the present invention is an improvement over the invention of Greenup aforesaid, and it comprises apparatus and supplemental steps of procedure whereby the articles may be produced, economically in quantity, for the trade.

The chief objects of the invention are to pro- 0 vide improved procedure and simple, efficient and durable apparatus for making rubber plates of the character mentioned. More specific objects are to provide for relatively large production without an excessive amount of apparatus; to reduce costs; to avoid the production of defective articles; to produce articles of attractive and uniform appearance; to effect uniformity of structure in the articles, and to conserve floor space. Other objects will be manifest. Of the accompanying drawings:-

Figure 1 is a plan view of apparatus embodying and adapted to carry out the invention, in its preferred form;

Figure 2 is a plan view thereof;

5 Figure 3 is a sectional view of a mold assembly taken on the line 3-3 of Figure 4;

Figure 4 is a vertical section through a mold assembly taken on the line 4-4 of Figure 3;

Figure 5 is a section on the line 5-5 of Figure 4;

Figure 6 is a front elevational view showingthe position of a mold during the filling thereof;

Figure 7 is a side elevation thereof as viewed from line l---'! of Figure 6;

Figure 8 is a sectional view of one end portion of a mold, and a filling attachment that is associated therewith during the mold-filling operation;

Figure 9 is a front elevation of apparatus for position, a part being in section;

ejecting finished work from a mold in inoperative Figure 11 is a view similar to Figure 9 showing the apparatus in operative position;

Figure 12 is a side elevation of the structure shown in Figure 11.

General description Referring particularly to. Figures 1 and 2 of the drawings, there is shown, somewhat diagrammatically, a layout of the apparatus embodying the invention and employed in carrying out the 1 improved method of manufacturing relatively stiff storage battery separator plates from rubber latex. The essential elements of the apparatus consist of molds A, a pair of latex storage and dispensing tanks 13, B, a battery of vulcanizers 15 or autoclaves C, C, fluid-control apparatus D for providing vulcanizing fluid to the vulcanizers, work-ejecting mechanism E for removing the finished work from the molds A, and apparatus, generally designated F, for cleaning the partition 20 plates of the molds between successive vulcanizing operations.

The molds A are assembled upon a table 40 that is positioned on the front side of the apparatus (the near side as viewed in Figures 1 and 2) adjacent the latex tanks B. A roller conveyor 4| extends along the front of the apparatus from the table 40 to the farthest vulcanizer C, to facilitate the moving of the molds from the table 4!] 'to either tank B, Where the molds are loaded, :13

and thence to any one of the vulcanizers C. A similar roller conveyor 42 extends along the rear of the apparatus to receive the molds as they are removed from the vulcanizers, and to facilitate the moving of the molds, to the right as 35 viewed in Figures 1 and 2, to a position beneath the work-ejecting mechanism E, the latter being positioned over conveyor 42. Short roller conveyors 43, 43 extend from conveyor 41 to conveyor 42, beneath the respective latex tanks B.

In continuation of the roller conveyor 42 at the right-hand end thereof, is an endless belt conveyor 45, and extending parallel to the latter, between it and the mold-plate cleaning apparatus F is an endless conveyor belt 43. Beside belt conveyor 45, near the end of roller conveyor 42, is a mobile tank 41 of cleaning fluid. An operator standing beside said tank 4'! receives the work as it is ejected from a mold, separates the pieces of Work from the mold plates, dips the 50 pieces of work in the tank 41 and then places them on conveyor 45, and places the mold plates on conveyor 46. A suction hood 48 is positioned over conveyor 45 to remove noxious odors arising from the work. The conveyor 45 moves slowly and pressure.

and the work thereon dries, said work being manually removed from the conveyor at the righthand end thereof. At the delivery end of conveyor 46 is a receptacle or sink 49 that receives the mold plates from the conveyor 46. The mold plates are manually washed in receptacle 49 and rinsed in a receptacle or sink 59 positioned beside it. The receptacle 59 is positioned at one end of plate cleaning device F, so that'the mold plates may be removed from said receptacle 59 and placed directly upon the said cleaning device F. The delivery end of the latter is beside moldassembling table 49. j 2' A I The later tanks The latex storage and dispensing tanks B are two in number to provide continuity of operation. Thus one of the tanks may be in use filling molds while the other is empty or being filled with a fresh charge of latex. The latex is compounded at a point removed from the apparatus, and comprises the usual or preferred constituents for effectingvulcanization in the presence of heat The molds The particular type of mold A employed in the invention is shown in detail in Figures 3, 4, 5 and in the Greenup patent 8. It comprises a rectangular metal box 52 having a removable bottom plate 53, a removable end plate 54 in one end thereof, and a plurality of metal molding plates 55, positionable within the boxupon the bottom plate 53 therein. The plates 55 are arranged to stand on'edge, in face to face relation, between the end plate 54 and the opposite end of the box, andto have slight clearance with the respective sides of the box. The plates 55 are compacted within the box 52 by means of a tightening screw 56 that is threaded through a bushing 51 that is mounted in the endwall of the box, behind the end plate 54-. The latter tapers toward its bottom margin, and the adjacent end-wall of the box is complementally sloped, the arrangement being such as to provide a draft for facilitating the removal of the work and the plates 55 from the box. There is an aper-' fine intervening molding cavities GI, 6|, Figure 8,

the latter being open at the top, and closed at the bottom by bottom plate 53. The molding cavities in the plates 55 are arranged to be filled with rubber latex that enters said cavities from the bottom thereof, and tothis end the top face of the bottom plate 53 is formed with two parallel grooves 92, 62 extending from end to end thereof. In that face of end plate 54 that abuts the end of box 52 there is formed two'spaced-apart vertical grooves 63, 63, and intersecting, transverse grooves 64, 94 that are contiguous with the top and bottom margins of the said plate. The upper groove 64 serves the purpose of receiving the nozzle of a removable trough-like filling attachment '65, Figures 6, 7 and 8 in the operation of filling the mold with latex. i 1

A suitable example of the com- The mold is filled with latex while the plates 55 are in un-compacted condition, as shown in Figures 3 and 8, said latex flowing through the grooves 63 and 64 of end plate 54 and grooves 62 of bottom plate 53, and then rising from the latter into molding cavities 6| between plates 55, with the result that there is little or no entrapped air in the mold. The latex in the filled mold preferably is agitated, as by tapping the mold with a hammer, to cause any bubbles in the latex to rise to the top. Thereafter the plates 55 are compacted, as shown in Figure 4, by setting up the screw 56.

The mold is provided with a cover of heavy duck or canvas 6'! and. a metal cover plate 68, the canvas cover 9'! resting upon the upper margin of the box 52, directly above the latex therein, and being held in place by cover plate 68. Both are applied just before the mold is placed in a vulcanizer C. The function of the canvas cover 91 is to absorb moisture of condensation that occurs when steam in. the vulcanizer comes into contact with the cold mold. In the absence of cover 51, such condensate might blemish the work or cause non-uniformity of its structure.

The work-ejecting mechanism The work-ejecting mechanism is shown in detail in Figures 12 to 15 inclusive to which attention now is directed. Said mechanism comprises a framework I81 that overhangs the roller conveyor 42, and suspended from said framework is a double-acting, fluid. pressure operated cylinder I38, the piston rod I89 of which extends down- Wardly. The respective ends of cylinder I88 are connected to inlet-and-outlet fluid-conducting pipes I99, I9I that extend to a manually-operated 4-way operating valve I92, the latter being connected to a fluid supply pipe I99. Swivelled on the lower end of piston rod I89 is a yoke I94, and extending downwardly from. the latter is a pair of brackets I95, I95 adapted to straddle a mold A and engage under suitable lugs projected laterally from the sidewalls of the mold, near the bottom thereof, as shown in Figures 14 and 15, during the operation of the ejector.

Mounted upon the yoke I94 is a vertically arranged, double acting fluid pressure operated cylinder I97, the piston rod I98 of which projects downwardly and has an axially apertured nozzle I99 mounted upon its lower end, the lower end of said nozzle being provided with an annular nose or gasket 299 of resilient material such as rubber. Fluid for operating the cylinder I9! is conducted to the respective ends thereof through flexible fluid conductor pipes 29I, 292 that have connection with a suitable manually operated control valve 293. The axial aperture in the nozzle I99 and gasket 299 constitute a delivery orifice for hydraulic pressure. Water is delivered thereto through a short pipe 294 projecting from the nozzle and carrying a manually operable valve 295, the latter having connection with a suitable source of hydraulic pressure through a flexible supply pipe 296.

The mold A as it comes from the vulcanizer has a heavy layer of vulcanized rubber over the tops of the mold plates 55 andthis requires to bescraped therefrom. Thereafter the mold is inverted upon a board 298, the tightening screw 56 is loosened, and the closure plug 59 is removed before the mold is advanced to the work-ejecting station.

The mold A on the board 298 is advanced enclwise to the work-ejecting station While the lowerend of the cylinder i9! is charged and supports the nozzle I99 in raised position, and the upper end of the cylinder 53B is charged so that the brackets I35 are in the lowered. position indicated by the broken lines in Figure 12. Thus the mold may be moved between the said brackets 95 and they will engage under the lugs projecting laterally from the mold. Then the fluid pressure in the cylinder 5 3'1 is reversed so that nozzle H9 is lowered until gasket 280' on the lower end thereof engages the bottom of the mold about the aperture 58 therein. Valve 205 is then operated to deliver hydraulic pressure through the nozzle E95, said pressure being applied, through the aperture in the mold bottom, against the bottom plate 53 in the mold. Fluid pressure in the cylinder tilt is then reversed to lift the brackets E95 to the position shown in full linesin Fig- 12 with the result that the mold box 521s lifted therewith and the bottom plate 53, end plate 54, mold plates 55, and the Work in the mold are ejected therefrom by the hydraulic pressure upon said bottom plate. Valve 205 is then operated to shut off the hydraulic pressure, and cylinder ifil' is reversed to move the nozzle Hi9 out of engagement with the bottom of the mold.

Overflow vulcanized rubber composition is then scraped from the sides and top of the ejected assembly, bottom plate 53 and end plate 54 are removed therefrom, and the molded structure consisting of the work and mold plates 55 is moved along to the end of roller conveyor 42 and onto endless conveyor 45. The latter may be moved intermittently if desired. Thereafter the cylinder I88 is reversed to lower the brackets I95 and mold box carried thereby. The mold veyor 46 and conveyed to the receptacle or sink 49 atthe delivery end thereof. The molded work is washed in the tank 41 and then placed on the conveyor 45, beneath the hood 48, which draws off the noxious fumes arising from the work.

7 Subsequently the molded work is moved to the delivery end of conveyor 45 and manually removed therefrom for further treatment.

Modification may be resorted to without departing from the spirit of the invention or the scope of the appended claims, which are not limited to the specific construction shown or exact procedure described. i

What is claimed is: 1. Vulcanizing apparatus comprising a mold comprising a box, a removable bottom plate therein, said bottom plate being formed with one or more grooves in its top face extending from end to end thereof, a removable end plate in the box,'and a plurality of removable, vertically arranged plates in the box defining vertical intermediate molding cavities, said end plate being formed with means permitting fluent vulcanizable material to flow between it and the adjacent wall of the box, whereby said material may reach the bottom plate and flow through the grooves therein and enter the molding cavities from the bottom thereof.

2. A combination as'defined in claim 1 including means for moving the end plate laterally to effect a compacting of the plates in the box.

3. In apparatus of the character described, a mold comprising-a box, a removable bottom plate of removable, vertically arranged separator plates in the box defining intermediate molding cavities, said end plate being formed with one or more vertical grooves to permit fluent vulcanizable material-to pass between the endplate and mold walland to reach the grooves of the bottom plate so astoflow through the latter and enter the molding cavities from the bottom thereof, and a screw threaded through the end wall of the mold into engagement with the end plate for compacting the separator plates in the box, said box being formed with a closable port in the bottom thereof through which fluid pressuremay be introduced to eject the contents of the box after the vulcanizable material therein has been vulcanized.

ROY W. BROWN. 

